Table 2. Results of testing of serial specimens obtained from a patient in Washington State infected with a Babesia divergens-like parasite^a.

Dateb	Examination of smears of whole blood for Babesia parasites	IFA titers to B. divergens antigensc	PCR
July 31, 2002	Positive (parasitemia level, 28.2%)	1:64	Positive
September 10	NPF	1:1,024	Positive
October 25	NPF	1:1,024	Positive
November 8	NPF	1:256	Negative
December 12	NPF	1:256	Negative
April 14, 2003	NPF	1:256	Negative

^aIFA, indirect fluorescent antibody; PCR, polymerase chain reaction; NPF, no parasites found.
^bSee Table 1 for values of other laboratory testing performed on or near dates listed here. Patient received antibabesial therapy from July 31 (before July 31 specimen obtained) through August 26, 2002. Hamsters injected with patient’s blood obtained July 31 and August 1 did not become demonstrably parasitemic, nor did jirds injected with blood from September 10.
^cAll of the serum specimens were tested at the Centers for Disease Control and Prevention on same day.